class_docstr: Reader for the OSISAF l3 netCDF format.
class_docstr_tok: ["Reader","for","the","OSISAF","l3","netCDF","format","."]
docstr: Set up the polar stereographic grid.
docstr_tok: ["Set","up","the","polar","stereographic","grid","."]
code: def _get_polar_stereographic_grid(self):
      """Set up the polar stereographic grid."""
      from pyresample import create_area_def
  
      try:
          proj4str = self["Polar_Stereographic_Grid/attr/proj4_string"]
      except KeyError:
          # Some products don't have the proj str, so we construct it ourselves
          sma = self["Polar_Stereographic_Grid/attr/semi_major_axis"]
          smb = self["Polar_Stereographic_Grid/attr/semi_minor_axis"]
          lon_0 = self[
              "Polar_Stereographic_Grid/attr/straight_vertical_longitude_from_pole"
          ]
          lat_0 = self[
              "Polar_Stereographic_Grid/attr/latitude_of_projection_origin"
          ]
          lat_ts = self[
              "Polar_Stereographic_Grid/attr/standard_parallel"
          ]
          proj4str = f"+a={sma} +b={smb} +lat_ts={lat_ts} +lon_0={lon_0} +proj=stere +lat_0={lat_0}"
      x_size = self["/dimension/xc"]
      y_size = self["/dimension/yc"]
      p_lowerleft_lat = self["lat"].values[y_size - 1, 0]
      p_lowerleft_lon = self["lon"].values[y_size - 1, 0]
      p_upperright_lat = self["lat"].values[0, x_size - 1]
      p_upperright_lon = self["lon"].values[0, x_size - 1]
      area_extent = [
          p_lowerleft_lon,
          p_lowerleft_lat,
          p_upperright_lon,
          p_upperright_lat,
      ]
      area_def = create_area_def(
          area_id="osisaf_polar_stereographic",
          description="osisaf_polar_stereographic",
          proj_id="osisaf_polar_stereographic",
          projection=proj4str,
          width=x_size,
          height=y_size,
          area_extent=area_extent,
          units="deg",
      )
      return area_def
  
file_path: satpy/satpy/readers/osisaf_l3_nc.py
imports: import logging
  from datetime import datetime
  from satpy.readers.netcdf_utils import NetCDF4FileHandler
label_desc: Use image node_id 3 for calling the OSISAFL3NCFileHandler obj's underlying member method code with example usage: obj._get_polar_stereographic_grid() and returns: area_def